Katz’s Revisability Paradox Dissolved

Quine's holistic empiricist account of scientific inquiry can be characterized by three constitutive principles: noncontradiction, universal revisability and pragmatic ordering. We show that these constitutive principles cannot be regarded as statements within a holistic empiricist's scientific theory of the world. This claim is a corollary of our refutation of Katz's [1998, 2002] argument that holistic empiricism suffers from what he calls the Revisability Paradox. According to Katz, Quine's empiricism is incoherent because its constitutive principles cannot themselves be rationally revised. Using Gärdenfors and Makinson's logic of belief revision based on epistemic entrenchment, we argue that Katz wrongly assumes that the constitutive principles are statements within a holistic empiricist's theory of the world. Instead, we show that constitutive principles are best seen as properties of a holistic empiricist's theory of scientific inquiry and we submit that, without Katz's mistaken assumption, the paradox cannot be formulated. We argue that our perspective on the status of constitutive principles is perfectly in line with Quinean orthodoxy. In conclusion, we compare our findings with van Fraassen's [2002] argument that we should think of empiricism as a stance, rather than as a doctrine.     

Possible-Worlds Semantics for Modal Notions Conceived as Predicates

If is conceived as an operator, i.e., an expression that gives applied to a formula another formula, the expressive power of the language is severely restricted when compared to a language where is conceived as a predicate, i.e., an expression that yields a formula if it is applied to a term. This consideration favours the predicate approach. The predicate view, however, is threatened mainly by two problems: Some obvious predicate systems are inconsistent, and possible-worlds semantics for predicates of sentences has not been developed very far. By introducing possible-worlds semantics for the language of arithmetic plus the unary predicate , we tackle both problems. Given a frame <W,R> consisting of a set W of worlds and a binary relation R on W, we investigate whether we can interpret at every world in such a way that A holds at a world wW if and only if A holds at every world vW such that wRv. The arithmetical vocabulary is interpreted by the standard model at every world. Several paradoxes (like Montague's Theorem, Gödel's Second Incompleteness Theorem, McGee's Theorem on the -inconsistency of certain truth theories, etc.) show that many frames, e.g., reflexive frames, do not allow for such an interpretation. We present sufficient and necessary conditions for the existence of a suitable interpretation of at any world. Sound and complete semi-formal systems, corresponding to the modal systems K and K4, for the class of all possible-worlds models for predicates and all transitive possible-worlds models are presented. We apply our account also to nonstandard models of arithmetic and other languages than the language of arithmetic.     

Corporate foreign exchange risk management: A study in decision making under uncertainty

This paper examines the management of foreign exchange risk in multinational corporations in light of the conclusions of previous empirical and theoretical investigations into decision making under uncertainty. Cognitive perceptions of risk and uncertainty are shown to underlie the hedging decisions made by corporate treasury managers, which are often demonstrably sub-optimal in a Bayesian expected utility framework. The findings suggest that simple principal-agent approaches to explaining seemingly sub-optimal corporate risk management preferences are inadequate inasmuch as they fail to account for the markedly different perspectives on risk and uncertainty taken by financial economists (qua economists) and corporate financial risk managers.     

What is wrong with Allais' Certainty Effect?

Several choice situations are constructed to explore whether the violation of expected utility theory in an Allais paradox choice situation can be attributed to what Tversky and Kahneman (1986) describe as the Allais certainty effect. Problems are developed where the Allais certainty effect would be expected to occur but results show it does not. Other problems demonstrate that the Allais ‘paradox’ is observed in the absence of the Allais certainty effect. The study concludes that, although expected utility theory is known to be wrong through the Allais paradox, the Allais certainty effect does not appear to be able to rescue it.     

Slippery Slopes and Collapsing Taboos

A slippery slope argument is an argument to this twofold effect. First, that if a policy or practice P is permitted, then we lack the dialectical resources to demonstrate that a similar policy or practice P* is not permissible. Since P* is indeed not permissible, we should not endorse policy or practice P. At the heart of such arguments is the idea of dialectical impotence, the inability to stop the acceptance of apparently small deviations from a heretofore secure policy or practice from leading to apparently large and unacceptable deviations. Using examples of analogical arguments and sorites arguments I examine this phenomenon in the context of collapsing taboos.     

A Propositional Logic with Relative Identity Connective and a Partial Solution to the Paradox of Analysis

We construct a a system PLRI which is the classical propositional logic supplied with a ternary construction , interpreted as the intensional identity of statements and in the context . PLRI is a refinement of Roman Suszko’s sentential calculus with identity (SCI) whose identity connective is a binary one. We provide a Hilbert-style axiomatization of this logic and prove its soundness and completeness with respect to some algebraic models. We also show that PLRI can be used to give a partial solution to the paradox of analysis. Presented by Jacek Malinowski     

行为决策中模糊规避研究的回顾与展望

模糊规避是指在相同奖赏的情况下,决策者会偏好有精确概率的事件而不是从主观上判断具有相同模糊概率的事件。自从Ellsberg提出模糊规避的概念以来,模糊规避已在行为决策研究的多个领域得到广泛验证。本文梳理了近五十年来关于模糊规避的研究文献,系统分析了模糊规避的研究范式、心理机制和影响因素,同时提出了未来的研究展望。     

模糊决策的情境依赖性

实验1采用艾尔斯伯格悖论的研究范式,探究被试对模糊的厌恶倾向以及在决策过程中所采用的决策策略。结果发现：被试对确定选项和模糊选项的选择存在差异;在肯定形式下倾向于确定选项,而在否定形式下则倾向于模糊选项,采用了利益最大化策略。实验2采用艾尔斯伯格悖论的变式,通过操纵概率和任务类型,发现：模糊决策具有情境依赖性,并非任何情况下个体都厌恶模糊。当风险选项不能满足自己的需要,即获胜机率比较小时,人们会偏向模糊选项。     

Soritic thinking, vagueness, and weakness of will

Soritic thinking based on reasoning that is involved in the sorites paradox plays a crucial role in some forms of weakness of will. Such soritic reasoning leads to failures of behavior, but cannot be shown to be irrational by standard means. Thus weakness of will appears to be rational, whereas strength of will is irrational when viewed soritically. The puzzle is how to undermine weakness of will and expose it as irrational. Even though such weakness of will is not moral, moral-type reasoning involving the principle of equality can be brought to bear. Weakness of will can also be seen to be analogous to free-rider problems and the prisoner's dilemma.     

Jump Liars and Jourdain’s Card via the Relativized T-scheme

A relativized version of Tarski’s T-scheme is introduced as a new principle of the truth predicate. Under the relativized T-scheme, the paradoxical objects, such as the Liar sentence and Jourdain’s card sequence, are found to have certain relative contradictoriness. That is, they are contradictory only in some frames in the sense that any valuation admissible for them in these frames will lead to a contradiction. It is proved that for any positive integer n, the n-jump liar sentence is contradictory in and only in those frames containing at least an n-jump odd cycle. In particular, the Liar sentence is contradictory in and only in those frames containing at least an odd cycle. The Liar sentence is also proved to be less contradictory than Jourdain’s card sequence: the latter must be contradictory in those frames where the former is so, but not vice versa. Generally, the relative contradictoriness is the common characteristic of the paradoxical objects, but different paradoxical objects may have different relative contradictoriness. Presented by Heinrich Wansing